[SPARK-46262][PS] Enable test for np.left_shift for Pandas-on-Spark…

… object

### What changes were proposed in this pull request?

This PR proposes to enable test for `np.left_shift` for Pandas-on-Spark object.

### Why are the changes needed?

Because now we completely support the PyArrow>=4.0.0, so the behavior difference within PyArrow<0.15 will not appear.

So we can enable the test since the behavior always same within the supported version as below:

```python
>>> pdf = pd.DataFrame({"A": [1, 2, 3, 4]})
>>> psdf = ps.DataFrame({"A": [1, 2, 3, 4]})
>>> np.left_shift(pdf, 1)
   A
0  2
1  4
2  6
3  8
>>> np.left_shift(psdf, 1)
   A
0  2
1  4
2  6
3  8
```

### Does this PR introduce _any_ user-facing change?

No, this just enables the test case.

### How was this patch tested?

The existing CI especially `NumPyCompatTests` should pass.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes apache#44178 from itholic/enable_np_left_shift.

Authored-by: Haejoon Lee <[email protected]>
Signed-off-by: Ruifeng Zheng <[email protected]>

python/pyspark/pandas/tests/test_numpy_compat.py

@@ -41,10 +41,6 @@ class NumPyCompatTestsMixin:
         "log1p",  # flaky
         "modf",
         "floor_divide",  # flaky
-        # Results seem inconsistent in a different version of, I (Hyukjin) suspect, PyArrow.
-        # From PyArrow 0.15, seems it returns the correct results via PySpark. Probably we
-        # can enable it later when Koalas switches to PyArrow 0.15 completely.
-        "left_shift",
     ]
 
     @property